The effects of ultra-high pressure (UHP) treatment on the chemical properties, colour and sensory quality
of young red wine were studied. UHP did not significantly affect the alcohol content, and the methanol
content was higher than that of the control, with the latter first increasing and then decreasing with the
increase in the pressure or period of treatment. The glycerol content was also markedly changed by UHP,
although without a regular pattern. The pH value was not markedly changed by the treatments, and the
contents of total acids and volatile acids were scarcely affected. The fructose and glucose contents were
clearly changed according to the different treatment conditions. The tartaric acid, citric acid and lactic
acid levels showed evident changes, whereas the malic acid level was not changed by UHP treatment. The
trend of these changes was similar to what occurs during natural ageing. As the pressure of the treatment
was increased to 200 MPa, the chroma value increased, followed by a decline upon higher pressure
treatments. The hue of the wine was significantly changed by treatment at different pressures, reaching
the highest value after treatment at 400 MPa and then decreasing with increasing pressure. The chroma
and hue values of the wine were changed significantly according to the duration of the UHP. After UHP, the
appearance, aroma and taste of the wine was improved, with the score for appearance obviously increased.
When the wine was treated at 500 MPa for 30 min, its sensory quality received the highest score.
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